Polarizing beamsplitters have numerous applications in optical systems, such as systems for freeform surface metrology. They are classically manufactured from birefringent materials or with stacks of dielectric coatings. We present a binary subwavelength-structured form-birefringent diffraction grating, which acts as a polarizing beamsplitter for a wide range of incidence angles −30∘…+30∘. We refine the general design method for such hybrid gratings. We furthermore demonstrate the manufacturing steps with Soft-UV-Nanoimprint-Lithography, as well as the experimental verification, that the structure reliably acts as a polarizing beamsplitter. The experimental results show a contrast in efficiency for TE- and TM-polarization of up to 1:18 in the first order, and 34:1 in the zeroth order. The grating potentially enables us to realize integrated compact optical measurement systems, such as common-path interferometers.

中文翻译：

---

纳米压印亚波长光栅作为偏振分束器

偏振分束器在光学系统中有许多应用，例如用于自由曲面测量的系统。传统上，它们是由双折射材料制成或与电介质涂层堆叠在一起。我们介绍了一种二元亚波长结构的形式双折射衍射光栅，该光栅在入射角−30∘…+30∘的宽范围内充当偏振分束器。我们改进了此类混合光栅的一般设计方法。我们进一步证明了使用软紫外-纳米压印光刻技术的制造步骤以及实验验证，该结构可可靠地用作偏振分束器。实验结果表明，TE极化和TM极化的效率在一阶中高达1:18，而在零阶中高达34：1。